The invention relates to a vehicle seat and more particularly, to a mechanism for allowing a seat bottom to slide and move forward when the seat back is tilted, thereby enlarging the opening or access aperture to a rear seat or compartment.
A vehicle seat, such as for a motor vehicle, of the type disclosed in German Patent No. DE 30 46 887 A1 is mounted on longitudinal rails along which it may slide, and its height is adjustable via linkage. The seat back is mounted so that it may swivel about the lower link point of the linkage at the guide rails, and is lockable in its normal rearward position with respect to the seat body. When the seat back is tilted forward, the seat body is displaced forward and upward so that the entry aperture or opening for a two-door vehicle is enlarged for the benefit of the back-seat passengers or access to a rear cargo area.
When the seat back is tilted backwards, the seat body automatically returns to its initial position. There is only a short lever of the rear linkage, and only a limited movement angle, available for seat body displacement along the vehicle direction of movement connected with the tilting movement of the seat back because of the locking of the linkage on the folding seat hardware. Therefore, the enlargement of the entry aperture is relatively small. Also, the design is complicated and expensive to implement. Finally, there is the disadvantage that the headrest may strike the headliner when the seat back is tilted forward, since the rear end of the seat back and the seat back are raised in such a case.
Based on this state of the art, the invention has the task of forming a vehicle seat of the known type so that its displacement upon tilting the seat back forward has positive function and is achieved using simple means.
The entry aperture to the back seat may be enlarged considerably by means of the invention disclosed herein. Relatively simple elements that have reliable function are used to displace the seat body and to lock it in the use position.
In one advantageous embodiment of the invention, the folding axis of the seat back remains at the same height so that a free folding movement of the seat back is insured.
The present invention features a seat having a seat displacement mechanism. A typical seat on which the present invention may be practiced includes a seat bottom and a seat back that is attached to the seat bottom so that it may be folded forward about a horizontal axis and locked in a use position. Front and rear linkages are mounted in pairs. Each front and rear linkage is pivotably attached proximate one end to said seat bottom and pivotably attached proximate a second end to a rail mechanism attached to a seat base. At least a portion of said rail mechanism includes an upper rail that is mounted so it may slide relative to a lower rail attached to said seat base.
A locking device is also provided, for locking at least one linkage from at least one of the pair of front and rear linkages into the use position. The upper rail includes, proximate at least one pair of the pairs of front and rear linkages, a longitudinal guide area into which the second end of the at least one pair of the front and rear linkage pairs may be inserted so that at least one of the pair of front and rear linkages may slide forward and be displaced longitudinally a predetermined distance while the other pair of linkages pivot when the locking device is released and the seat back is tilted forward.